SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92e894b98a933968cbbb70b3eb36d2263da88d24abf88d65d2b51e5664a4b9b0' 
  AND token = 'x8taIv7/f6wLukk/wtSTpvGJhnjyCwfaCISqvm4iFJs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}